We propose a bidirectional ultra‐wideband (UWB) over multi‐mode fiber link for internet of things based smart home applications that is compatible with globally emerging green radio trend. Employing direct modulation and coupled with carrier‐reuse makes the proposed architecture cost efficient. UWB signals are all‐optically generated by converting phase modulation to intensity modulation by using a shaping filter that has a Gaussian profile. Bidirectional data at the rate of 2 Gbps is transmitted while achieving low receiver sensitivities.